Yellow azo dyestuffs.



UNITED STATES PATENT OFFICE.

PAUL VOLKMANN, OF LEVERKUSEN. NEAR COLOGNE, GERMANY, ASSIGNOR TOSYNTHETIC PATENTS 00., INC.. 013 NEW YORK. N. Y., A CORPORATION OFPatented June 2, 1914.

NEW YORK.

YELLOW, AZO DY ESTUFFS.

1,098,600. Specification of Letters Patent.

1 no Drawing.

Application filed August 7. 1913. Serial No 783,541.

To all 'wizom iii-may concern: I

-Be itknown that I, PAUL Vomnrcxxx, doctor of philosophy, chemist,citizen of the German Empire, residing at Leverkusen,

near' Cologne, Germany, have invented new pyrazolone-4tor 5-sulfonicacid or with aceto-acetic acid ester and condensingthe resultmgcompounds with Q-chloroarylhydraz1n sulfonic acids.

The new coloring matters dye wool from an acid bath 1n grecmslryellowlevel pure shades characterized by their good fastness to light. Thedyes have in a free state most probably the formula:

(1t meaning the radical of a toluene comin the presence of 110 parts ofCaC O The copulation completed 22 parts of sodium carbonate are addedand the mixture is fil-Q tcred from CaSO and CaCO The resulting solutionis then added to a suspension of 222.5 parts of2-chloro-phenylhydrazinst-sulfonic acid in 8500 parts of watercontaining 35 parts of sodium carbonate and U6 parts of sodium acetate.The mixture is heated to 95 C. during 3 hours, acidulated with 70partsof hydrochloric acid of 19.5" B. and the dye is salted out from thehot mixture. It has the formula:

and is in the shape, of its sodium salt a yel low powder soluble inconcentrated sulfuric acid with a yellow coloration. Upon reduc tionwith stannous chlorid and hydrochloric acid the dye is decomposed,2-toluidin-5- sulfonic acid and 2-chloro-et-sulfophenyl-3-methyl-4L-amino-5-pyrazolone are obtained. It produces on wool brightgreenish-yellow level shades fast to light.

I claim 1. The new azo dyes derivable from a diazotized toluidincompound and a Q-chlorophenylsulfo-methylpyrazolonc having in a freestate most probably the formula:

soas in which It represents the toluene radical of v the diazotized'toluidin compound, which dyes are after being dried and pulverizedpowders soluble in water and in concentrated sulfuric acid with a yellowcoloration; yielding upon reduction with stannous chlorid andhydrochloric acid a toluidin compound and 2 chloro sulfophenyl 3methyl-t-amino-Zi-pyrazolone; and dyeing wool from an acid bath ingreenish-yellow level pure shades characterized by a good fastness tolight. substantially as described.

The new azo dye derivable from diazotized '12 -tolui(lin- 5 sulfonicacid and 2- chloi'o-l-sulf0phenyl-3-1nethyl- 5 -pyrazolone of thefollowing formula:

SO3H(4) i i i l i l 2 10 which dye is after being dried and pulverizedin the shape of its sodium salt a yellowiSll powder soluble inconcentrated sulfuric acid with a yellow color; yielding upon reoeeeooWitnesses.

PAUL VOLKMANN, [15.] Witnesses HELEN News, ALBERT N JF sR

